Penguin decays of B mesons

TL;DR

This paper reviews penguin decays of B mesons, highlighting their role in testing the Standard Model and probing for new physics through various experimental measurements and theoretical insights.

Contribution

It provides a comprehensive overview of penguin decay processes, experimental searches, and their implications for the Standard Model and beyond.

Findings

Measurements of b -> s gamma and B -> K* gamma support Standard Model predictions.

Observations of B -> K pi and related decays constrain new physics models.

Future experiments will further explore penguin decay phenomena.

Abstract

Penguin, or loop, decays of B mesons induce effective flavor-changing neutral currents, which are forbidden at tree level in the Standard Model. These decays give special insight into the CKM matrix and are sensitive to non-standard model effects. In this review, we give a historical and theoretical introduction to penguins and a description of the various types of penguin processes: electromagnetic, electroweak, and gluonic. We review the experimental searches for penguin decays, including the measurements of the electromagnetic penguins b -> s gamma and B -> K* gamma and gluonic penguins B -> K pi, B+ -> omega K+ and B -> eta' K, and their implications for the Standard Model and New Physics. We conclude by exploring the future prospects for penguin physics.